1. Field of the Invention
The present invention relates to a multiple cast-in insert apparatus for concrete, and more particularly, to a multiple cast-in insert apparatus for concrete, in which an anchor for installing various structures is coupled to the concrete so that multiple functions are provided by one apparatus, and thus convenience of construction is enhanced.
2. Discussion of Related Art
Generally, in a concrete pouring operation, a cast is manufactured according to a shape of a building and installed at a pillar forming a frame of the building, and concrete is poured, and if the concrete is dried and cured, the cast is removed.
At this time, an anchor for constructing various structures is coupled to a ceiling of the building formed by the concrete. The anchor may be inserted and coupled into an insert buried in the concrete.
In a method of burying the insert in the concrete, there are a post-install method in which a hole is bored after curing of the concrete, and then the insert is installed in the hole, and a cast-in method in which the insert is disposed at a position, in which the anchor will be installed, in advance, and then the concrete is poured. The cast-in method is mainly used.
FIG. 1 is an exemplary view of a conventional insert.
As illustrated in FIG. 1, the conventional insert 1 has an anchor hole formed in a lower surface thereof. A lower end of the insert 1 is installed at a bottom surface of a cast, concrete c is poured and cured, the cast is removed, an anchor a is coupled in the exposed anchor hole, and then various structures are installed.
At this time, the structures include a duct, a ceiling frame, an electric wiring, and so on. When the various structures are installed at the anchor a, and then a ceiling plate is coupled to the ceiling frame, construction of the ceiling is completed.
However, since the conventional insert 1 has a high supporting force against a load of the anchor a, but the anchor a is directly in contact with and supported by a surface portion of the concrete c, there is a problem in that a crack may be easily generated at the anchor, when a transverse pressure is applied to the anchor a.
Further, since the generated crack is usually propagated to an inner side of the anchor, a coupling force with the insert 1 is weakened, and a supporting force of the concrete c may be reduced.
Also, since a gap is frequently generated between the cast and a lower surface of the insert 1 due to foreign substances, the concrete c may be easily introduced into the anchor hole, and a screw thread formed in the anchor hole may be damaged when the introduced concrete c is removed, and thus it is difficult to install the anchor a.
And in order to construct a connection rebar protruding through a side portion using the concrete, a hole is formed in a side wall portion of the cast, and the connection rebar is inserted, and then the concrete is poured. However, the cast is damaged due to the hole, and thus it is impossible to reuse the cast.
Meanwhile, when a rebar is placed in the concrete c to increase the supporting force of the concrete, a separate rebar spacer is required to place the rebar which is spaced a predetermined height from the cast.
Thus, since an additional material cost and an installation period of time are required to provide and install the insert 1 for installing the anchor a and the rebar spacer for placing the rebar, a construction cost and a period of time are increased. Further, since unnecessary devices are inserted into the concrete c, the supporting force of the concrete c is reduced.
Furthermore, since a thickness of a concrete slab is changed according to a purpose and a size of the building, the spacer should be separately provided and installed to correspond to a changed arrangement distance of the rebar.
Meanwhile, when the concrete c is poured, a leveler such as a height indicating bar is used to check a thickness of the poured concrete through confirmation of levelness of a concrete pouring surface. At this time, separate products having various dimensions corresponding to a state of a bottom surface or a poured height of the concrete should be produced, or a product having a long dimension should be cut and installed according to a dimension of a corresponding construction. When the product having the long dimension is used, there is inconvenience in a work, for example, in which a protruding portion thereof should be removed after a pouring operation of the concrete.
As described above, when the concrete c is poured, in order to separately provide and install the insert 1, the rebar spacer, and the leveler according to a design of the building, the design and the construction become complicated, and the construction cost and period of time are also increased, and thus it is difficult to efficiently perform the construction.